The purpose of this study is to identify possible biochemical markers in patients with cancer of the large bowel, chronic ulcerative colitis and other premalignant colon lesions. The parameters studied will be arysulfatases A and B, lactic acid dehydrogenase (LDH), and dihydrofolate reductase (DHFR), alkaline phosphatase, DNA, and carcinoembryonic antigen (CEA). Colonic washings, colon-rectal tissue biopsies, 24-hour urine collections and blood from normal subjects and patients diagnosed to have colon-rectal carcinoma, ulcerative colitis, familial polyposis, and other premalignant colon lesions will be assayed for the above biochemical parameters. Preliminary data from our laboratory suggests that there are increases in the arylsulfatases and alkaline phosphatase activities in colonic washings from patients with large bowel cancer as compared to normal controls. The CEA values in the colonic washings from patients that were normal controls, with CUC and with large bowel cancer. Arylsulfatase A appears to be more useful than the B isoenzyme and correlates better with the disease process. We have automated the arylsulfatase A and B assays and plan to develop rapid assays for these enzymes that might allow their use for random urine specimens. No correlation between the enzyme activities or CEA values for colonic washings and urine or plasma in the same patient were noted. The values obtained for the latter two fluids appeared to reflect the stage of the disease process. The usefulness of serum, urine and colonic CEA and hydrolytic enzymes in the management of ulcerative colitis and predicting early malignant changes in the large bowel is the overall goal of this project. Bibliographic references: L.R. Morgan, L.E. Gillen, B.E. Maddux and E.T. Krementz. Arylsulfatase in Colorectal Carcinoma and Response to 5-Fluorouracil. Proc. Amer. Assoc. Cancer Res. 16: 151, 1975. L.E. Posey and L.R. Morgan. Urine Arylsulfatase A Activity in Normal and Cancerous Populations: Manual Method Versus New Automated Method. Southeast Section, Amer. Assoc. Clin. Chemists, October, 1975.